TITLE: GCN CIRCULAR NUMBER: 16887 SUBJECT: GRB 141004A: RATIR Optical Observations DATE: 14/10/05 09:34:12 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141004A (D'Elia, et al., GCN 16878) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/10 5.30 to 2014/10 5.35 UTC (7.82 to 9.15 hours after the BAT trigger), obtaining a total of 1.07 hours exposure in the r and i bands. We detect the source reported by Swift/UVOT (D'Elia, et al., GCN 16878) and the 3.6m TNG telescope (D'Elia, et al., GCN 16881). We obtain the following detections: r 22.35 +/- 0.13 i 22.11 +/- 0.12 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the earlier TNG observations we note that the GRB has faded with an approximate temporal power-law index of t^(-1.0). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.